diff --git a/idea/idea-analysis/src/org/jetbrains/kotlin/idea/stubindex/IdeStubIndexService.java b/idea/idea-analysis/src/org/jetbrains/kotlin/idea/stubindex/IdeStubIndexService.java
index 40b1ef766ad..df855b74132 100644
--- a/idea/idea-analysis/src/org/jetbrains/kotlin/idea/stubindex/IdeStubIndexService.java
+++ b/idea/idea-analysis/src/org/jetbrains/kotlin/idea/stubindex/IdeStubIndexService.java
@@ -44,7 +44,7 @@ import java.util.List;
 public class IdeStubIndexService extends StubIndexService {
 
     @Override
-    public void indexFile(KotlinFileStub stub, IndexSink sink) {
+    public void indexFile(@NotNull KotlinFileStub stub, @NotNull IndexSink sink) {
         FqName packageFqName = stub.getPackageFqName();
 
         sink.occurrence(KotlinExactPackagesIndex.getInstance().getKey(), packageFqName.asString());
@@ -70,27 +70,15 @@ public class IdeStubIndexService extends StubIndexService {
                 if (partSimpleName == null) {
                     continue;
                 }
-                FqName multifileClassPartFqName = packageFqName.child(Name.identifier(partSimpleName));
-                sink.occurrence(KotlinMultifileClassPartIndex.INSTANCE.getKey(), multifileClassPartFqName.asString());
+                FqName multiFileClassPartFqName = packageFqName.child(Name.identifier(partSimpleName));
+                sink.occurrence(KotlinMultifileClassPartIndex.INSTANCE.getKey(), multiFileClassPartFqName.asString());
             }
         }
     }
 
     @Override
-    public void indexClass(KotlinClassStub stub, IndexSink sink) {
-        String name = stub.getName();
-        if (name != null) {
-            sink.occurrence(KotlinClassShortNameIndex.getInstance().getKey(), name);
-        }
-
-        FqName fqName = stub.getFqName();
-        if (fqName != null) {
-            sink.occurrence(KotlinFullClassNameIndex.getInstance().getKey(), fqName.asString());
-
-            if (stub.isTopLevel()) {
-                sink.occurrence(KotlinTopLevelClassByPackageIndex.getInstance().getKey(), fqName.parent().asString());
-            }
-        }
+    public void indexClass(@NotNull KotlinClassStub stub, @NotNull IndexSink sink) {
+        processNames(sink, stub.getName(), stub.getFqName(), stub.isTopLevel());
 
         if (stub.isInterface()) {
             sink.occurrence(KotlinClassShortNameIndex.getInstance().getKey(), JvmAbi.DEFAULT_IMPLS_CLASS_NAME);
@@ -100,22 +88,28 @@ public class IdeStubIndexService extends StubIndexService {
     }
 
     @Override
-    public void indexObject(KotlinObjectStub stub, IndexSink sink) {
-        String name = stub.getName();
-        if (name != null) {
-            sink.occurrence(KotlinClassShortNameIndex.getInstance().getKey(), name);
+    public void indexObject(@NotNull KotlinObjectStub stub, @NotNull IndexSink sink) {
+        processNames(sink, stub.getName(), stub.getFqName(), stub.isTopLevel());
+
+        indexSuperNames(stub, sink);
+    }
+
+    private static void processNames(
+            @NotNull IndexSink sink,
+            String shortName,
+            FqName fqName,
+            boolean level) {
+        if (shortName != null) {
+            sink.occurrence(KotlinClassShortNameIndex.getInstance().getKey(), shortName);
         }
 
-        FqName fqName = stub.getFqName();
         if (fqName != null) {
             sink.occurrence(KotlinFullClassNameIndex.getInstance().getKey(), fqName.asString());
 
-            if (stub.isTopLevel()) {
+            if (level) {
                 sink.occurrence(KotlinTopLevelClassByPackageIndex.getInstance().getKey(), fqName.parent().asString());
             }
         }
-
-        indexSuperNames(stub, sink);
     }
 
     private static void indexSuperNames(KotlinClassOrObjectStub<? extends KtClassOrObject> stub, IndexSink sink) {
@@ -138,6 +132,9 @@ public class IdeStubIndexService extends StubIndexService {
         }
     }
 
+    // Drop suppression and fix warning after abandoning 173 branch
+    // BUNCH: 173
+    @SuppressWarnings({"ConstantConditions", "CastCanBeRemovedNarrowingVariableType"})
     @Nullable
     private static KotlinModifierListStub getModifierListStub(@NotNull KotlinClassOrObjectStub<? extends KtClassOrObject> stub) {
         StubElement<?> childStub = stub.findChildStubByType(KtStubElementTypes.MODIFIER_LIST);
@@ -148,7 +145,7 @@ public class IdeStubIndexService extends StubIndexService {
     }
 
     @Override
-    public void indexFunction(KotlinFunctionStub stub, IndexSink sink) {
+    public void indexFunction(@NotNull KotlinFunctionStub stub, @NotNull IndexSink sink) {
         String name = stub.getName();
         if (name != null) {
             sink.occurrence(KotlinFunctionShortNameIndex.getInstance().getKey(), name);
@@ -176,7 +173,7 @@ public class IdeStubIndexService extends StubIndexService {
     }
 
     @Override
-    public void indexTypeAlias(KotlinTypeAliasStub stub, IndexSink sink) {
+    public void indexTypeAlias(@NotNull KotlinTypeAliasStub stub, @NotNull IndexSink sink) {
         String name = stub.getName();
         if (name != null) {
             sink.occurrence(KotlinTypeAliasShortNameIndex.getInstance().getKey(), name);
@@ -194,7 +191,7 @@ public class IdeStubIndexService extends StubIndexService {
     }
 
     @Override
-    public void indexProperty(KotlinPropertyStub stub, IndexSink sink) {
+    public void indexProperty(@NotNull KotlinPropertyStub stub, @NotNull IndexSink sink) {
         String name = stub.getName();
         if (name != null) {
             sink.occurrence(KotlinPropertyShortNameIndex.getInstance().getKey(), name);
@@ -226,7 +223,7 @@ public class IdeStubIndexService extends StubIndexService {
     }
 
     @Override
-    public void indexAnnotation(KotlinAnnotationEntryStub stub, IndexSink sink) {
+    public void indexAnnotation(@NotNull KotlinAnnotationEntryStub stub, @NotNull IndexSink sink) {
         String name = stub.getShortName();
         if (name == null) {
             return;
@@ -237,7 +234,10 @@ public class IdeStubIndexService extends StubIndexService {
         if (fileStub != null) {
             List<KotlinImportDirectiveStub> aliasImportStubs = fileStub.findImportsByAlias(name);
             for (KotlinImportDirectiveStub importStub : aliasImportStubs) {
-                sink.occurrence(KotlinAnnotationsIndex.getInstance().getKey(), importStub.getImportedFqName().shortName().asString());
+                FqName importedFqName = importStub.getImportedFqName();
+                if (importedFqName != null) {
+                    sink.occurrence(KotlinAnnotationsIndex.getInstance().getKey(), importedFqName.shortName().asString());
+                }
             }
         }
     }
@@ -298,11 +298,15 @@ public class IdeStubIndexService extends StubIndexService {
     @Override
     public KotlinFileStub deserializeFileStub(@NotNull StubInputStream dataStream) throws IOException {
         StringRef packageFqNameAsString = dataStream.readName();
+        if (packageFqNameAsString == null) {
+            throw new IllegalStateException("Can't read package fqname from stream");
+        }
+
         boolean isScript = dataStream.readBoolean();
         StringRef facadeStringRef = dataStream.readName();
         StringRef partSimpleName = dataStream.readName();
         int numPartNames = dataStream.readInt();
-        List<StringRef> facadePartNames = new ArrayList<StringRef>();
+        List<StringRef> facadePartNames = new ArrayList<>();
         for (int i = 0; i < numPartNames; ++i) {
             StringRef partNameRef = dataStream.readName();
             facadePartNames.add(partNameRef);